Hydraulic bumper jack



Dec. 26, 1950 J, C, SQHWANTNER 2,535,759

HYDRAULIC BUMPER JACK I u ver/tor DCC- 25, 1950 J. c. scHwANTNERHYDRAULIC BUMPER JACK '2 Sheets-Sheet 2 Filed Sept. 25, 1945 Inventorfo-$6796 Car? Schl/e222" 71er Patented Dec. 26, 1950 HYDRAULIC BUMPER JACK Joseph Carl Schwantner, Chicago, Ill., assigner of one-half to HelenSchwantner, Chicago, Ill.

Application September 25, 1945, Serial No. 618,525

1 Claim.

This invention relates to a `bumper jack and more particularly to alifting jack for elevating a motor vehicle to facilitate the changing oftires and similar operations.

The primary object of the invention is to enable a vehicle of theautomotive type to be elevated so that one or more of its `Wheels may bemoved clear of the ground so that various operations may be performedthereon.

Another object of the invention is to facilitate the elevation of thevehicle with ease through the use of hydraulic pressure, and to preventthe building up of too great a pressure when the jack has attained itsgreatest height.

Among its features, the invention embodies a vertical column carrying,at its upper end, a piston and at its lower end a liquid reservoir, acylinder slidable on the piston, and means to force liquid from thereservoir through the piston and into the cylinder to elevate thelatter.

Other features include an adjustable hook carried by the cylinder forengagement With a portion of the frame, such as the bumper of thevehicle to be elevated, a manually controlled valve for establishingcommunication between the interior of the cylinder and reservoir topermit the lowering of the jack and the load imposed thereupon undercontrolled conditions, and an automatic release valve operated by thecylinder to return the iluid to the reservoir when the Y cylinder hasattained its greatestheight on the piston. i

In the drawings- Figure 1 is a view of a bumper jack embodying thefeatures of this invention, certain portions thereof being shown insection to more clearly illustrate the details of construction,

Figure 2 is a horizontal sectional View taken substantially on line 2-2of Figure 1,

Figure 3 is a fragmentary side View of the upper end of the cylindershowing the adjustable hook,

Figure 4 is a horizontal sectional View taken substantially on the line4-4 of Figure 1,

Figure 5 is a, horizontal sectional view taken substantially on the line5--5 of Figure 1,

Figure 6 is a sectional View taken substantially on the line 6 5 ofFigure 5, and

Figure 7 is a fragmentary enlarged sectional view through the piston andcylinder.

Referring to the drawings in detail, my improved jack, designatedgenerally lll, cornprises a tubular column il provided, at its upperend, With a head I2 carrying a suitable packing l 3 to form a piston.The head l2 is formed with a concentric bore I .4 into which the upperend of a vertically extending, concentric pipe l5 is anchored in anysuitable manner. Welded or otherwise secured to the lower end oi thetubular column ll is a reservoir l5, and the lower end of the pipe l5extends to the bottom of the reservoir, as vvill be readily understoodupon reference to Figure l. Welded or otherwise secured to the column llintermediate its ends is a spider l'l to Which stabilizing legs lil arepivotally attached, as at i9. As illustrated in Figures l and 6, thelower end of the pipe l5 is closed and formed adjacent the lower endthereof is a transverse bore 25 which terminates axially of the pipe ina verticalbore, the upper end of which is formed with altaperedvalveseat 2| which opens into the bore in the pipe' l5 and is adapted toreceive a ball check valve 22 which serves to prevent iluid entering thepipe through the bore 2l! from iiowing in a reverse direction. Formed inthe pipe l5 above the ball valve 22 is a radial tapered passage 22 whichforms the seat for a needle valve '23 operable through a suitablepacking gland 25 in the side Wall of the reservoir l5 by means of a handWheel 25. It will thus-be seen that liquid entering the column throughthe transverse bore 2@ may be returned to the reservoir I5 bymanipulation of the needle valve 23, Formed on the inner face of theWall of the reservoir I5 is a pump case 26 provided with a vertical bore2l in which, a piston 28 is mounted for reciprocation. The lower end ofthe bore 2 communicates through a transverse `bore V2li with a suitablepipe 35, the opposite end of which opens into the bore 2li so that asthe piston 28 is reciprocated Within the bore 27, the fluid from thereservoir taken into the bore 21 through a suitable check valve 5I willbe ejected through the pipe Sie and into the pipe I5 through the ballvalve 22. Pivoted at 33 to the column ll above the upper end of thereservoir l5 is a lever 35 to Which the upper end of the piston rod 35carried by the piston 28 is pivoted, as at 35. This lever is providedwith a socket 3l into Which a handle 53 is adapted to be fitted tofacilitate the operation of the pump mechanism just described.

Mounted for vertical sliding movement on the head l2 is a cylinder 39,the upper end of which is closed, as at 45, to form a chamber il withinthe cylinder into which the fiuid flowing through the pipe I5 isintroduced for causing the cylinder to move` vertically on the head l2.Threaded or otherwise secured to the lower end of the cylinder 39 is aguide ring 42 which cooperates with the column II in preserving thecylinder in proper alignment on the column I I.

Formed in the head I2 parallel with but offset from the bore I4 is abore 43 formed at its upper end with a valve seat 44 and havingcommunicating therewith a passage 45, the opposite end i which opensinto the interior of the column II around the pipe I5. The lower end ofthe bore 43 is closed by anfapertured plug 46 in which the stem of avalve 41 is slidably mounted in such a manner that the lower end thereofprojects below the general level of the underside of the head I2, and inthe path of the ring 42 so that when the cylinder 39 is moved to itshighest point of elevation, the stem or the valve 4l will be engaged bythe ring 42 so as to unseat the Valve and establish communin cationbetween the chamber 4I and the reservoir I6.

Mounted for vertical adjustment on the cylinder 39 is a clamping ring 48to which a suitable suspension hook 49 is attached. This hook may beformed directly upon the ring 43 if so desired, but I nd it preferablelto arrange for its self-alignment by providing the ring 4S atdiametrically spaced points with pivot pins or trunnions 50 to which anintermediate ring 5i is pivotally attached. The ringflcarries, atdiametrically opposed points and arranged on axes perpendicular to theaxes of the trunnions o 50, radial pivot pins or trunnions 52 uponWhichan outer ring 53 carrying the hookLlQ is pivotally attached. Itwill thus be seen that the Yhook 49 may be mounted for universalmotionon the ring 48 so as to automaticallyadjust itself to properposition beneath a bumper when the jack is in use.

In operation, it will be understood that 4the jack is positioned inapproximately proper relation beneath the bumper of a vehicle with thelegs I8 extended, as illustrated in Figure 1, so as to lend stability tothe structure. The legs I8 are of such length that theyserve to sustainthe weight of the jack as well as to lend stability to the column II andVhaving positionedfthe jack. beneath the bumper-of the vehicle to belifted, the valve 23 is closed and the lever 31 is manipulated to causethe piston 28 to reciprocate with-` in the cylinder 27. Reciprocation ofthe piston causes the liquid to flow through the valve 3i and into thecylinder 27 and thence out through the pipe 30 and into the pipe I5through the ball check valve 22. The fluid rising in the pipe I entersthe chamber 4I through the head I2 and thus exerts a lifting pressure onthe cylinder 39. This causes the hook 49 engaging* the bumper to riseand consequently lift the weight of the vehicle. In order to prevent toogreat a pressure being developed Within the chamber-4I when the cylinderhas risen to its upper limits,

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4 the valve 4'! vis brought into play by engagement of the ring 42 withthe stem of said valve, thus opening the latter and establishingcommunication between the chamber 4I and the reservoir I5 through thespace within the column II surrounding the pipe I5. When it is desiredto lower the jack and the load carried thereby, the hand wheel 25 isrotated to open the valve 23 so vas to establish communication betweenthe interior of the pipe I5 and the reservoir I6 and permit rthe iluidto return from the interior of ythe cylinder to the reservoir undercontrolled conditions.

While in the foregoing there has been shown and described the preferredembodiment of this invention, it is to be understood that minor changesin the details of construction and combination and arrangement of partsmay be resorted to Without departing from the spirit and scope of theinvention as claimed.

What I claim is:

In a hydraulic jack, a liquid reservoir, a tubular column extendingvertically from the reservoir, the lower end of the tubular columnopening into the reservoir, a piston carried by and closing the upperend of the tubular column, a cylinder mounted on the piston to slideverticali'` means extending axially through the piston to feed liquidunder pressure upwardly into the cylinder above the piston, said pistonhaving a passage therein opening through its top and into the'interiorof the column, a check Valve in the passage to arrest the ow of liquidthrough the passage from the cylinder to the column, a Valve stern onthe check valve and extending through the-bottom of the piston and guidemeans on the cylinder and encircling the column to guide the cylinder asit moves on the piston 'and to engage the valve stem and open the checkvalve when the cylinder reaches a predetermined height on the piston.

JOSEPH CARL SCHWANTNER.

REFERENCES CITED The following references are of record in the rile ofthis patent:

UNITED STATES PATENTS Great Britain Mar. 30, 1933

